<!DOCTYPE html><html lang="en">
<head>    
<title>@yield('title')</title>  
<meta charset="utf-8">    
<meta name="viewport" content="width=device-width, initial-scale=1">    
<meta http-equiv="x-ua-compatible" content="ie=edge">    <link rel="stylesheet" href="https://cdn.rawgit.com/twbs/bootstrap/v4-dev/dist/css/bootstrap.css">
<style type="text/css">
        div{
            width:100%;
        }
    </style>
</head>
<body>
@include('test.header')

@section('sidebar')
            This is the base sidebar.
@show
{{--变化的内容块--}}
@yield('content')

@include('test.footer')
</form>
</body>
</html>